package com.sky;

/**
 * @author : wushikai
 * <p>
 * date : 2021/8/7
 */
public class Calc {


    public static void main(String[] args) {
        System.out.println("1+1=2");
        System.out.println(new String("abc").substring(0, 1));
    }


    public static  void add(Integer i ,  Integer j){
        System.out.println(i + j );
    }




}
